1. Field of the Invention
The present invention relates to a transfer carrier for a flexible printed circuit board for holding and transferring flexible printed circuit boards on each of which a semiconductor device and small parts are mounted, and also relates to an electronic parts mounting method on a flexible printed circuit board.
2. Description of Related Art
Since a film-shaped thin circuit board such as a flexible printed circuit board on which electronic parts are mounted is hard to be treated by itself, the film-shaped thin circuit boards are usually treated in a state that a plurality of the flexible printed circuit boards are held on a plate-shaped transfer carrier. Electronic parts are also mounted on such the flexible printed circuit boards in a state that the flexible printed circuit boards are held on the transfer carrier. Thus, the transfer carrier used in an electronic parts mounting process is required to have a positioning function for holding the flexible printed circuit boards with preferable positioning accuracy.
The electronic parts to be mounted on the flexible printed circuit board are not limited to ones of the same mounting method but there is a case that the electronic parts are mounted on the same flexible printed circuit board with different mounting methods. For example, there is a case that small parts such as resistors and capacitors to be mounted through the reflow soldering are mounted on the same flexible printed circuit board together with a semiconductor device such as a flip chip to be mounted through the bonding method. The transfer carrier for holding such a type of the flexible printed circuit board is desirably provided with heat resisting property so as to be usable in the reflow process together with the aforesaid positioning function.
However, conventionally, it is difficult to realize such a transfer carrier provided with both the preferable positioning function and heat resisting property, and hence the transfer carriers dedicated for the respective mounting methods are required. That is, it is required to perform such a procedure that the flexible printed circuit boards on which the semiconductor devices were bonded are removed from a transfer carrier for bonding and the flexible printed circuit boards are transferred on another transfer carrier for soldering. Thus, it is necessary to prepare plural kinds of the transfer carriers for respective kinds of the flexible printed circuit boards. As a result, there arises a problem that the cost of the equipment increases, and it is troublesome to transfer the flexible printed circuit boards on the way of the mounting process to another transfer carrier and so the manufacturing efficiency is degraded.